Olive Tree Root Systems

Olive trees feature shallow roots and tall crowns.

The olive tree (Olea europaea) is a suitable addition to a Mediterranean garden or landscape, producing not only a tall and wide crown but also valuable fruit. Thriving in U.S. Department of Agriculture plant hardiness zones 9 through 11, this tree also grows extensively underground, sending roots out for nutrition and moisture.

Root Type

While other trees send their roots deep into the ground, olive trees feature shallow root systems. This allows olive roots to collect water from soil that typically dries fast, ensuring the tree gets enough moisture to stay hydrated. While shallow root systems get water faster, they can also become exposed more easily. This leaves them open to damage from the elements and from landscaping tools such as lawn mowers and weed trimmers. Checking the olive tree periodically and after rains will ensure that roots stay buried and safe.

Moisture Requirement

Although olive tree roots sit close to the surface, the tree is remarkably drought-tolerant and can survive on little water for days and even weeks. Still, for the best growth and fruit production, a well-watered olive tree is ideal. Ensuring that an olive tree gets up to 1 inch of water every week will keep roots moist and provide a steady stream of hydration and nutrition.

Nutrients

Olive trees grow in a variety of soils and often require fertilizing only once in the spring, when the growing season begins. Poor growth during the growing season may indicate the need for additional fertilizer in the summer, but over-fertilization can lead to root burn, which can damage the plant.

Space

Partly due to their expanding tree crown above ground, olive trees require approximately 20 feet between plantings. This also benefits the root system, since it means the soil is otherwise untouched for a 20-foot radius. Nutrients in the topsoil are preserved for the growing olive tree.

Dangers

Salt buildup in the soil as well as roots exposed to severely low temperatures can cause olive roots to die back and may, if not controlled, threaten the olive tree. Additionally, invertebrate pests such as the nematode can infiltrate the roots of an olive tree, causing infection and cutting off nutrients to the plant. Using pre-sterilized soil and keeping a close eye on the tree can help minimize damage from environmental and animal threats.

About the Author

Sean Russell has been writing since 1999 and has contributed to several magazines, including "Spin" and "Art Nouveau." When not writing, Sean helps maintain community gardens in Silver Lake and Echo Park, California. Russell also worked extensively on the restoration and rejuvenation of public parks in Florida, Louisiana and Mississippi after damage from 2004-2005 hurricanes.